Ertson



(No. Model O. E. ROBERTSON.

' STEAM ENGINE.

No. 357,231. Patented-Feb. 8, 1887. F191 Fig.2.

, Q -I v imam- "UNiTED STATES PATENT ()FFIcE.

CHARLES E. ROBERTSON, or M'oN REAnouEB o, CANADA.

T STEAM- ENGINE.

SPECIFICATION forming part. of Letters Patent No. 357,231, dated February 8, 1887.

7 Application filed September 9, 1886. Serial No. 213,146. (No model.) Patented in England January 1 6, 1886, No. 689, and in v Canada August 16,1886, No. 24,750.

invented new and useful Improvements in Steam-Engines; and I do hereby declare that the follo'wing'is a full, clear, and exact description of the same.

' This invention has reference to improvements in the class of steam-engines known as triple-cylinder engines and the invention consists in an improved construction of cylinder and the arrangement of the valves-and I steam-passages therewith, all as will be hereinafter fully set forth and claimed.

In the drawings hereunto annexed similar letters of reference indicate like parts,-and

Figure 1 is a vertical central section of a triple .cylindrical extensions of it.

cylinder and valves embodying my invention. Fig. 2 is a half front elevation of the cylinder shown in Fig. 1. Fig. 3 is a plan of the cylinder shown in Fig. 1.

The cylinder is made in three parts, A, B, and O. The cylinder A is of theordinary type of three-ported cylinder, having an exhaust-port, E, and two steam-ports, F, so that.

the steam with which it will be supplied will act upon both sides of the piston G. The cylinder B is formed integral with the cover H of the cylinder A. It is provided with one steam-passage, I, which serves both for steamand exhaust, as the steam with which this cyl-,

inder is provided only acts on one side of the piston K. The cylinder 0 is formed, as shown, in one with the small cover L, and extends into the cylinder A in the form of a longitudinal sleeve centrally situated within the cylinder, A-that is to say, the axes of the two cylinders are in one and the same line. In the cover L and extension thereof is formed a port, M, which serves both for steam and exhaust, as this cylinder, like the cylinder B, is single acting.

N is the steam-chest proper. O and P are Qis an ordinary short D-valve secured upon the valve-stem R, This valve stem is provided with piston-valves S, T, and U, the action of which will be hereinafter more par; ticularly described.

V is a side pipe by which connection is formed between the two extensions 0 and I of the steam-chest. G, the piston of the cylinder A, is made'in one with a trunk, A, the outside of which serves as a piston to thecylinder B, while the inside of the trunk is large enough to pass over the cylinder 0.

O is a sleeve or trunk which is attached to the end of the trunk A, preferably by the piston-rod D, and this forms the piston 0fthe cylinder 0.

The steam from the boiler is first admitted, in the ordinary manner, to the extension]? through an opening indicated by the dotted circle at E, Fig. l, and as the valve-stem and valves, which move together, are moved in an ordinary manner, (by any suitable or usual means,) the steam is at the proper times and I chest N by the valve '1; (or any'other means' such as packing'may be provided for this purpose.) It is therefore obliged to pass by the opening F and pipe V into the extension 0, Where, the valve U being in the required .position, it passes into the cylinder B by the passage I, and, having therein performed'its function, it returns down the passage I into the steam-chest N, from which it is admitted by valve Q into the cylinder A in the ordinary manner, and finally escapes by the port, E into the condenser or atmosphere, as the case may be.

In arranging the passages F, I, and M, and valves S, Q, and U, and their laps, care must betaken to have them suitable for an equal stroke to agree with the'stroke of the valve-stem R and to adjust and attach them to the proper positions on the va'lvestem.

The advantages of this construction of triple-cylinder are economy in fuel, economy in space occupied by the engine, and the simplification of the engine in its parts, as only one eccentric or link motion and crank is reand M of a triple cylinder, the valves Q, U, 10 quired. and S, with one valve-stem, R, by which all What I claim isthe said valves are operated, substantially as 1. The combination of a triple eylinderhavdescribed.

5 ing passages and pistons, as described, with steam-chest N, having extensions 0 and 1? CHARLES ROBERTSON and valves Q, U, and S, the whole substan- Vitnesscs: tiallly as described. HENRI E. DowiiL,

2. In combination with the ports F, E, I, CHARLES G. J. SIMPsoN. 

